The present invention is directed to transparencies, and more specifically, to high projection efficiency, fire resistant, low haze, lightfast and waterfast ink jet transparencies with improved ink absorption and ink spreading when used in combination with liquid ink compositions and solid ink hot melt ink compositions such as those selected for ink jet printing processes, and thermal transfer printing. In embodiments of the present invention, the transparencies are comprised of a supporting substrate, such as paper, or MYLAR.TM., and thereover two coatings, a first coating layer which comprises a binder having a melting point in the range of from about 100.degree. C. to about 275.degree. C. and preferably from about 150.degree. C. to 260.degree. C., and a heat dissipating fire retardant compound, and a second dye immobilizing light resistant, water resistant ink receiving coating layer situated so that the first coating layer is between the second dye immobilizing, light resistant, water resistant ink receiving coating layer and the substrate, the second coating layer being comprised of a blend of a polymer, cationic monomeric or polymeric component capable of complexing with the dyes of the ink compositions, a lightfastness inducing agent, and or mixtures thereof, a filler, a biocide and an ink spreading agent of fluoro compounds, especially aliphatic and aromatic compounds containing from 1 to about 25 fluorine atoms, and having a melting point of between 50.degree. C. to 100.degree. C. and preferably wherein the two coatings, thus a total of four coatings, are present on each surface of the supporting substrate.
With the transparencies of the present invention, there are enabled a number of advantages, including the important advantages of high projection efficiency due primarily to improved flow of the liquid and solid hot melt inks on the ink receiving layers containing low surface energy fluoro compounds, and more specifically, in view of the low surface tension, about 30 to about 35 dynes/centimeter of the ink receiving layer. With the transparencies of the present invention, there are enabled a number of other advantages, including the important advantage of fire retarding characteristics for the transparencies when used in ink jet printers that employ heat or microwave energy for drying inks, low haze, that is, for example, wherein the transparencies permit greater than 95 percent of the light to be transmitted therethrough in embodiments, and which transparencies possess excellent lightfastness and waterfastness characteristics. The transparencies of the present invention can be selected for ink jet methods and apparatus, which employ hot melt wax based inks.
U.S. Pat. No. 4,801,473 and U.S. Pat. No. 4,877,676, the disclosures of each of which are totally incorporated herein by reference, disclose hot melt ink transparencies which include a transparent substrate of a polyester material, an ink pattern disposed on one surface of the transparent sheet in the form of three-dimensional ink spots having curved surfaces, and a transparent layer covering the ink spots which has an index of refraction approximately the same as that of the ink spots. The transparent layer is applied to the substrate and the ink spots in the form of a liquid coating which wets the surfaces of the substrate and ink spots and spreads over them to produce a transparent layer having a maximum deviation of about 20 degrees from a plane parallel to the substrate.
U.S. Pat. No. 4,775,594, the disclosure of which is totally incorporated herein by reference, discloses a polyester ink jet recording sheet for the production of a transparency obtained by coating the sheet with a clear layer including a nonvolatile organic acid selected from citric acid, glycolic acid, malonic acid, tartaric acid, maleic acid, fumaric acid, malic acid, and succinic acid. A coating composition for preparing the clear layer on the recording sheet is preferably comprised of, in addition to the organic acid, a water soluble resin selected from poly(vinylpyrrolidone), poly(acrylic acid), polyacrylamide, hydroxyethyl cellulose, carboxymethyl cellulose, and vinyl acetate-vinylpyrrolidone copolymer, a water insoluble resin selected from polyesters, poly(vinylbutyral)resin, polyketone resins, carboxylated resins, nitrocellulose polymers, styrenated acrylic polymers, allyl alcohol-styrene copolymers, and a fluorinated surfactant having the formula R.sub.f CH.sub.2 CH.sub.2 S CH.sub.2 CH.sub.2 N+(CH.sub.3).sub.3 CH.sub.3 SO.sub.4 - or (R.sub.f CH.sub.2 CH.sub.2 O) P(O)(ONH.sub.4).sub.2 or (R.sub.f CH.sub.2 CH.sub.2 O).sub.2 P(O)(ONH.sub.4) wherein R.sub.f .dbd.F(CF.sub.2 CF.sub.2).sub.3-8.
U.S. Pat. No. 4,956,225 discloses a transparency suitable for electrographic and xerographic imaging which comprises a polymeric substrate with a toner receptive coating on one surface thereof comprising blends selected from the group consisting of poly(ethylene oxide) and carboxymethyl cellulose; poly(ethylene oxide), carboxymethyl cellulose, and hydroxypropyl cellulose; poly(ethylene oxide) and vinylidene fluoride/hexafluoropropylene copolymer; poly(chloroprene) and poly(alpha-methylstyrene); poly(caprolactone) and poly(alpha-methylstyrene); poly(vinyl isobutyl ether) and poly(alpha-methylstyrene); poly(caprolactone) and poly(p-isopropyl alpha-methylstyrene); blends of poly(1,4-butylene adipate) and poly(alpha-methylstyrene); chlorinated poly(propylene) and poly(alpha-methylstyrene); chlorinated poly(ethylene) and poly(alpha-methylstyrene); and chlorinated rubber and poly(alpha-methylstyrene).
U.S. Pat. No. 4,997,697 discloses a transparent substrate material for receiving or containing an image which comprises a supporting substrate base, an antistatic polymer layer coated on one or both sides of the substrate and comprising hydrophilic cellulosic components, and a toner receiving polymer layer contained on one or both sides of the antistatic layer, which polymer comprises hydrophobic cellulose ethers, hydrophobic cellulose esters, or mixtures thereof, and wherein the toner receiving layer contains adhesive components.
U.S. Pat. No. 5,624,743, the disclosure of which is totally incorporated herein by reference, discloses a transparency comprised of a supporting substrate, thereover a first coating layer comprised of a binder having a glass transition temperature of less than about 55.degree. C., a cellulosic viscosity modifier, a lightfastness inducing agent and a biocide; and a second ink-receiving coating layer comprised of a hydrophilic binder, an oxyalkylene containing compound, a dye mordant, an optional filler, and an optional biocide; and wherein the first coating is in contact with the substrate and is situated between the substrate and the second ink coating, and which transparency possesses a haze value of from about 1 to about 10 and a lightfastness value of from about 80 to about 95.
U.S. Ser. No. 5,672,424, the disclosure of which is totally incorporated herein by reference, discloses a transparency comprised of a supporting substrate, thereover a first coating layer comprised of an anionic layer that adheres well to the substrate; and a second cationic layer situated on the top of the first anionic layer that binds with the anionic layer and comprised of cationic quaternary monomers as well as polymers and a lightfastness inducing agent; and a third ink receiving layer situated on the top of the second cationic layer and comprised of block copolymers and graft polymers, a biocide and a filler; which transparency possesses a haze value of from about 0.5 to about 10 and a lightfastness value of from about 95 to about 98.
U.S. Ser. No. 5,683,793 the disclosure of which is totally incorporated herein by reference, discloses a transparency comprised of a supporting substrate, thereover a first coating layer comprised of an ink absorbing layer and a biocide; and a second inkspreading coating layer comprised of a hydrophilic vinyl binder, a dye mordant, a filler, an optional lightfastness inducing agent and an ink spot size increasing agent selected from the group consisting of hydroxy acids, amino acids and polycarboxyl acids; and wherein the first coating is in contact with the substrate and is situated between the substrate and the second ink coating, and which transparency possesses a haze value of from about 0.5 to about 10 and a lightfastness value of from about 95 to about 98.
The disclosures of each of the patents and applications recited herein are totally incorporated herein by reference in their entirety.
While the above transparencies are suitable for their intended purposes, a need remains for improved high projection efficiency such as a projection efficiency greater than 90 percent. In addition, a need remains for fire resistant transparencies particularly suitable for use in ink jet and electrophotographic applications that employ heat and microwave energy to fix inks and toners. In addition, a need remains for transparencies that can be used in printers that employ solid hot melt inks. In addition, a need remains for transparencies with excellent low haze characteristics, such as haze value of between from about 0.5 to about 10 and preferably between 0.5 to 5, a feature not easily obtained considering that the total thickness of the two layered coatings can range from about 2 to about 50 microns and average about 25 microns. There is also a need for improved waterfastness and excellent lightfastness in the range of from about 80 to about 98 percent, and a need for transparencies wherein colors can be satisfactorily projected. A need also remains for transparencies which are particularly suitable for use in printing processes wherein the recorded transparencies are imaged with liquid and solid inks and dried by exposure to radiant heat or microwave radiation. Further, there is a need for transparencies coated with a discontinuous, porous film. There is also a need for transparencies which, subsequent to being imaged with an aqueous liquid or solid ink, exhibit reduced curling. These and other needs are achievable with the transparencies of the present invention in embodiments thereof.